Field of the Invention
The present invention relates to pistons and to methods for their manufacture and in particular to the reinforcement of piston ring grooves.
Conventional pistons for internal combustion engines are provided with grooves for the accommodation of piston rings. However, the sides of the grooves may suffer wear and deformation due to the inertia effects of the piston rings as the piston is reciprocated during use. This deformation is a particular problem in aluminium pistons. In order to prevent deformation, reinforcing rings can be fixed to one or both sides of the piston ring groove, for example as described in British Patent Specification No. 1,441,984. The reinforcing rings have hitherto been fixed in position by chemical bonding or by welding.